Task Panes

These sit alongside your office document letting you display contextual information.
For example it could look up, retrieve and display data from web services
You are able to read and write to documents
You are able to handle certain application and user events
These applications run in a sidebar alongside your Office content such as a Word Document, Excel Spreadsheet or PowerPoint presentation.
These can provide both contextual feedback based on the current state of the document, as well interactivity by presenting a custom user interface that can read and write data in the document via the JavaScript API.

The default width of the vertical task pane is 300px
The name of the add-in is displayed in the top left corner.
If the user clicks a command to open another task pane the original task pane is replaced.

Manifest Version 1.1 - VersionOverrides

Command button showing a task pane

<OfficeApp xsi:type="TaskPaneApp"> 
   <VersionOverrides> 
      <Hosts> 
         <Hosts> 
            <DesktopFormFactor> 
               <ExtensionPoint> 
                  <CustomTab> 
                     <Group> 
                         <Control> 

<Action xsi:type="ShowTaskpane"> 
   <TaskpaneId>TaskPane_Id1</TaskpaneId> 
   <SourceLocation resid="----" /> 
</Action> 
</VersionOverrides>

Manifest Version 1.0 - DefaultSettings

<OfficeApp xsi:type="TaskPaneApp"> 
   <DefaultSettings> 
      <SourceLocation DefaultLocation="---.html"/> 
   </DefaultSettings> 
</OfficeApp>

scrollbar does not appear in task pane
change is CSS styling applied to the <body> element
include the -ms-overflow style property, set it to scrollbar